from datetime import datetime

from sqlobject import *

from turbogears import identity 
from turbogears.database import PackageHub

hub = PackageHub("openmedx2")
__connection__ = hub

# class YourDataClass(SQLObject):
#     pass

class Visit(SQLObject):
    class sqlmeta:
        table="visit"

    visit_key= StringCol( length=40, alternateID=True,
                          alternateMethodName="by_visit_key" )
    created= DateTimeCol( default=datetime.now )
    expiry= DateTimeCol()

    def lookup_visit( cls, visit_key ):
        try:
            return cls.by_visit_key( visit_key )
        except SQLObjectNotFound:
            return None
    lookup_visit= classmethod(lookup_visit)

class VisitIdentity(SQLObject):
    visit_key = StringCol(length=40, alternateID=True,
                          alternateMethodName="by_visit_key")
    user_id = IntCol()


class Group(SQLObject):
    """
    An ultra-simple group definition.
    """
    
    # names like "Group", "Order" and "User" are reserved words in SQL
    # so we set the name to something safe for SQL
    class sqlmeta:
        table="tg_group"
    
    group_name = UnicodeCol(length=16, alternateID=True,
                            alternateMethodName="by_group_name")
    display_name = UnicodeCol(length=255)
    created = DateTimeCol(default=datetime.now)

    # collection of all users belonging to this group
    users = RelatedJoin("User", intermediateTable="user_group",
                        joinColumn="group_id", otherColumn="user_id")

    # collection of all permissions for this group
    permissions = RelatedJoin("Permission", joinColumn="group_id", 
                              intermediateTable="group_permission",
                              otherColumn="permission_id")


class User(SQLObject):
    """
    Reasonably basic User definition. Probably would want additional attributes.
    """
    # names like "Group", "Order" and "User" are reserved words in SQL
    # so we set the name to something safe for SQL
    class sqlmeta:
        table="tg_user"

    user_name = UnicodeCol(length=16, alternateID=True,
                           alternateMethodName="by_user_name")
    email_address = UnicodeCol(length=255, alternateID=True,
                               alternateMethodName="by_email_address")
    display_name = UnicodeCol(length=255)
    password = UnicodeCol(length=40)
    created = DateTimeCol(default=datetime.now)

    # groups this user belongs to
    groups = RelatedJoin("Group", intermediateTable="user_group",
                         joinColumn="user_id", otherColumn="group_id")

    def _get_permissions(self):
        perms = set()
        for g in self.groups:
            perms = perms | set(g.permissions)
        return perms
        
    def _set_password(self, cleartext_password):
        "Runs cleartext_password through the hash algorithm before saving."
        hash = identity.encrypt_password(cleartext_password)
        self._SO_set_password(hash)
        
    def set_password_raw(self, password):
        "Saves the password as-is to the database."
        self._SO_set_password(password)



class Permission(SQLObject):
    permission_name = UnicodeCol(length=16, alternateID=True,
                                 alternateMethodName="by_permission_name")
    description = UnicodeCol(length=255)
    
    groups = RelatedJoin("Group",
                        intermediateTable="group_permission",
                         joinColumn="permission_id", 
                         otherColumn="group_id")


